Question

The mean kinetic energy of a molecule at $O^{0}C$ is $5.621\times {10}^{-14}erg$. Calculate Boltzmann's constant. If the value of $R=8.314\times {10}^{7}erg$, then calculate the no. of molecules present in one mole of gas.

Answer 1

$\frac{3}{2}k\times T=5.621\times {10}^{-14}$

$\Rightarrow \frac{3}{2}\times k\times 273=5.621\times {10}^{-14}$

$\Rightarrow k=\frac{5.621\times 2\times {10}^{-14}}{3\times 273}$

$\Rightarrow k=1.372\times {10}^{-16}$ erg

$\Rightarrow \frac{R}{N_A}=1.372\times {10}^{-16}erg$

$\Rightarrow N_A=6.059\times {10}^{23}$